Mechanism for locking and fault detection in an electrical vehicle supply equipment cord reel

ABSTRACT

An electric vehicle charging assembly includes a cord reel, a cord reel locking mechanism, and a master control unit for selectively unlocking the cord reel in response to an authorization signal. The electric vehicle charging assembly monitors the rotational position of the cord reel to prevent unauthorized use, and to record or relay information related to the improper use or malfunction of the electric vehicle charging assembly.

The present application is a continuation of application Ser. No.15/979,239 filed May 14, 2018, now U.S. Pat. No. 10,358,044 which is acontinuation of application Ser. No. 14/968,145 filed on Dec. 14, 2015,now U.S. Pat. No. 9,969,278 which is a continuation of Ser. No.13/968,247 filed on Aug. 15, 2013, now U.S. Pat. No. 9,211,799.

FIELD OF THE INVENTION

The present invention relates generally to management of security for aretractable cord reel apparatus delivering electrical power to avehicle, and more specifically to ensuring the safety of the system andthe user while preventing the tampering or vandalism of such anapparatus and/or providing notice to the service provider of any suchtampering or short event. Cords used for charging batteries in, forexample, electric cars, may be used with the present invention when notin use to safely store the cord and protect it from the elements anddamage.

A retractable cord reel may be part of a charging station in, forexample, a parking lot at an airport or in a home or office garage. Thecharging station may be a post or other suitable structure containingthe cord reel and associated circuitry.

The cord reel assembly described here relates to improved features forimproving the security of the cord from vandalism or similar safetyissues, with the ability to prevent unspooling of the cord reel in theabsence of a card swipe or other recordable event. The invention furtherrelates to the ability to sense and avoid safety issues arising out ofthe failure of cord reel to retract in the event of mechanical failureor the like. The invention also relates to the ability to report to aremote service facility for these and similar events for servicing.

BACKGROUND OF THE INVENTION

Retractable cord reels have been used in various applications toretractably store various types of cables. Typically, a reel might havea stationary end and a retractable end, the retractable end capable ofextension from and retraction back into the reel, and which can beconnected to, for example, a battery in an electric vehicle. Using areel provides convenient storage for the cord. The reel also protectsthe cord from damage, since it need not be left on the ground. Damage tothe cord is reduced. The hazard presented to a user by a damagedelectrical cord is also avoided.

The use of a reel has a disadvantage, because such mechanisms involveadditional moving parts which, by definition, incrementally increase thepotential for malfunction over time or through misuse. In addition,while it may be possible to lock the handle with a locking mechanism soas to provide a secure connection between the interface chargerconnector and the electric vehicle, or between interface chargerconnector and a storage point or holder, such a locking mechanism wouldnot, by itself, preclude the ability of a vandal to unspool the cordreel and cut the cord in order to obtain the copper contained therein.To date, however, there are no available products for preventing theunauthorized unspooling of a cord reel in an electric vehicle chargingstation, nor is there any mechanism for detecting failures associatedwith the cord reel mechanism in such a cord reel system.

DEFINITION OF TERMS

The following terms are used in the claims of the patent as filed andare intended to have their broadest plain and ordinary meaningconsistent with the requirements of the law:

A “retractable cord reel” refers to a cable storage unit and cablemanagement systems having a spooling cord such as the type found in U.S.Pat. No. 5,094,396 to Burke, the subject matter of which is herebyincorporated by reference, and U.S. Patent Application No. 2007/0262185to Burke, the subject matter of which is also hereby incorporated byreference.

An electric vehicle means any vehicle, including one propelled solely bya rechargeable battery, and one using hybrid propulsion including arechargeable battery.

An “encoder” means any device use to locate the position of a cord reel,including but not limited to optical, resistive, or digital sensors.

An “authorization signal” means any signal which facilitates the lockingor unlocking of a cord reel, including but not limited to a signal fordiscontinuing a default lock mechanism, a signal for actively changingthe lock status, or

Where alternative meanings are possible, the broadest meaning isintended. All words used in the claims set forth below are intended foruse in the normal, customary usage of grammar and the English language.

SUMMARY OF THE INVENTION

The present invention relates to one or more of the following features,elements or combinations thereof.

One disclosed embodiment is directed to improvements in a retractablecord reel for battery charging stations, including those used forvehicles propelled at least in part by rechargeable batteries. Thecharging station includes an electric cord connected to a source ofpower. When used in a public location, storing the cord on a reel helpsprotect against theft of the cord for its copper such that the chargingstation can require use of a credit card swipe, key card or similarmeans to allow use of the station. The present invention particularlyprovides a mechanism for locking the reeling or unreeling of a cordwithout a card swipe or similar signal which authorizes the unreeling ofthe cord and provides a record of the party responsible for the cord insuch an event.

Another embodiment of the present invention further includes safetyfeatures for enabling the notification of a remote service entity ifthere are any failures or impediments in the cord reel retraction systemcausing a loss of retraction. Examples of events leading to a retractionfailure sensed by the system could be a broken mainspring, a damaged orfouled cord or a foreign body in the retraction mechanism. The inventionalso includes an additional proximity sensor and locking mechanism usedto secure the charger interface connector (such as a SAE J1772connector) into its stowage receptacle.

Thus, it can be seen that one object of the disclosed invention is toprovide a mechanism for identifying a responsible party in the event ofact of vandalism to the charging station system, and in particular tothe charging cord of the charging station system.

A further object of the present invention is to preclude the unspoolingof the cord in the absence of a card swipe or similar authorizingactivity.

Another object of the invention is to detect damage to the cord, orremoval of the cord.

Still another object of the present invention is to provide for thereporting of vandalism or malfunction events to a remote servicinglocation.

It should be noted that not every embodiment of the claimed inventionwill accomplish each of the objects of the invention set forth above.For instance, certain claimed embodiments of the invention will notrequire the detection of malfunction events. In addition, furtherobjects of the invention will become apparent based upon the summary ofthe invention, the detailed description of preferred embodiments, and asillustrated in the accompanying drawings. Such objects, features, andadvantages of the present invention will become more apparent in lightof the following detailed description of an example embodiment thereof,and as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially exposed perspective figure of a cord reelsubassembly and charger interface connector in an electric vehiclecharging station in accord with another preferred embodiment of thepresent invention;

FIGS. 2a and 2b are perspective figures of a cord reel subassemblymounted to a support for an electric vehicle charging station in accordwith one preferred embodiment of the present invention;

FIG. 3 is an exploded view of a vehicle connector with a lockingmechanism in accord with a preferred embodiment of the presentinvention; and

FIG. 4 is a schematic showing the connection in operation between themaster control unit and the enocoder, the card swipe mechanism, and thefirst and second solenoids of a preferred embodiment of the presentinvention.

FIG. 5 is a ground fault detection circuit and self-test mechanismaccording to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

As can be seen in FIG. 1, a charging system 10 includes a cord realsubassembly 20, a housing 40, and a vehicle connector 60. The housing 40preferably contains or is otherwise attached to a master control unit(MCU) 50 as detailed in FIGS. 4 and 5, and described in greater detailbelow. In this embodiment, because the battery is used for propulsion ina vehicle, vehicle connector 60 is constructed in accordance with SAESurface Vehicle Recommended Practice J1772, “SAE Electric VehicleConductive Charge Coupler,” issued by the Society of AutomotiveEngineers for electric vehicles. For different applications notinvolving an electric vehicle, connector 16 need not comply with J1772,and its design can be modified as required by the intended use.

As shown in FIG. 2, the cord reel subassembly 20 preferably includes aseries of apertures 22 to enable the spool 24 of the cord reel to belocked into a specific rotational location to the housing 40 or asimilar fixed support. The physical locking of the cord reel will beenabled by a solenoid 26 which slidably engages one of the apertures 22and an encoder 28 which is adjacent to the spool 24. The encoder 28 willread marks 30 on the spool 24 indicating the rotational status of thespool 24, i.e., the degree to which the cord 32 is wound or unwound. Theencoder 28 communicated readings of the marks 30 to a MCU 50, as shownin FIG. 4. The MCU 50 provides an authorization signal to the solenoid26, causing the solenoid 26 to slide through aperture 22 into locked orunlocked positions as desired.

As further shown in FIG. 4, the unlocking of solenoid 26—which, in turn,permits or causes the cord 32 to be wound or unwound—may be initiated bythe MCU 50 in response to receiving an authorization signal input from acard swipe device 52, which may be alternative mechanisms including akey fob, phone swipe mechanism and/or similar user authorizationinterface. The MCU 50 can further compare the input from the encoder 28with the presence or absence of the authorization signal so as todetermine if an unauthorized unwinding of the cord 32 (e.g., vandalismor theft) is taking place. The MCU 50 can, in the instance of such anevent, record the time of the event and/or the identity information ofthe last user so as to determine (potentially) the identity of thevandal or thief. Alternatively, the MCU 50 can communicate theunauthorized use event via a remote communication module 52, such a wificonnection or the like, to a remote service facility so as to enable therepair or replacement of the assembly 10 right away. As a furtheralternative, the MCU 50 can provide a deactivation signal in the eventof an unauthorized use so as to prevent the flow of current through thecord 32.

Those of skill will understand that this system 10 will further accountfor the presence of malfunctions in the cord reel subassembly 20, suchas a malfunction of the spring (not shown) which could be detected bythe encoder 28 through the failure of the cord 32 to retract.

As shown in FIG. 5, an alternative embodiment of the present inventionfurther provides a ground fault detection circuit 54, which may belocated on the same printed circuit board, or is otherwise operativelyconnected to or integrated with MCU 50. The ground fault detectioncircuit 54 provides protection to the user and to the device fromdangerous conditions that can arise in the field either externallythrough an unintended path through which current can flow and atdifferent subassembly levels, such as a failed current transformer 58 orwiring connecting that part to circuitry that resides on a circuitboard, or the circuitry itself. A self testing scheme of this entiresystem provides a guarantee of safety of the above subassemblies.Following a successful test, a higher level of safety and lower overallrisk is provided.

In this embodiment, the self test may be accomplished through a commandfrom the Microcontroller unit 50 which sends a pulse signal to atransistor 56 that is connected to a specific resistance value, RSET,and a given power supply 62, e.g., 12V. This voltage and resistancegenerate a corresponding current that is passed through currenttransformer 58, as well as amplifier 64, which is the same circuitryused to detect and signal the existence of genuine Ground Faultconditions.

As yet another further alternative feature, the MCU 50 can furtherprovide signals which enable the system 10 to recover from ground faultconditions more readily. Specifically, where a genuine ground faultcondition has occurred, e.g., where a ground fault happens whilecharging the vehicle. In such an instance, the MCU 50 will send a signalopening relay 68 to discontinue charging such that the vehicle coupleror connector 60 will not deliver a charge, so as to preserve the safetyof the charging locale. However, simply leaving the circuit open in theevent of a transient ground fault condition may create an unintendeddeleterious effect of stopping the charging event where a user is not inattendance to observe such conditions (e.g., an overnight charge). Thus,in such a situation, it is desirable for the MCU 50 to automaticallyreinitiate the charging event at a short, predetermined interval bysending a second signal to close the relay 68. Thus, in this alternativeembodiment, the MCU 50 automatically avoids any long term disabling ofthe system 10 because of transient ground fault events.

As a variant of handling transient ground fault conditions, a furtheralternative embodiment could be provided for the MCU 50 to disable andreengage the system 10 in the event of a transient ground faultcondition in the act of connecting the vehicle connector 60 to thevehicle, i.e., at the beginning of the charging process. If a groundfault condition were sensed (via the current transformer 58 describedabove), the MCU 50 could generate a signal opening the relay 68, whilebasing the timing for reinitiating the charging process upon disengagingthe vehicle connector 60 from the vehicle. That is, rather than having apreset time for reinitiating after detecting the ground fault event oropening the relay, the MCU could sense the vehicle connector 60 beingdisengaged and time the restart of the ability to charge to somepreselected time thereafter.

As a further alternative embodiment referenced in FIGS. 3 and 5, thesystem 10 can include a second solenoid 66 for locking the vehicleconnector 60 to a holder 70 in the absence of an authorization signal,the authorization signal being provided from the MCU 50 in the manner asdescribed above.

When used for charging an electric vehicle, the preferred embodiment ofthe system described herein is a Level 1 charger, as that functionalityis described by the California Air Resources Board and codified in title13 of the California Code of Regulations, the U.S. 1999 NationalElectrical Code section 625 and in SAE International standards. Suchsystems use lower voltage and are therefore less expensive and suitablefor use at a home or other locations where 120 volt AC power is readilyavailable. Due to the relatively low voltage, charging times are longer,possibly as much as ten to twelve hours for a full recharge of anelectric vehicle battery. However, those of skill will understand thatthe present invention as defined by the claims covers not only Level 1chargers, but also chargers designated as (for instance) Level 2 underthose same standards.

Card swipe device and remote communication module 52 are connected toMCU 50 which can be programmed by one of skill in the art. One suitablemicrocontroller for the MCU is an Atmel ATMEGA328P from AtmelCorporation of San Jose, Calif.

While the disclosure is susceptible to various modifications andalternative forms, specific exemplary embodiments thereof have beenshown by way of example in the drawings and have herein been describedin detail. It should be understood, however, that there is no intent tolimit the disclosure to the particular embodiments disclosed, but on thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the disclosure asdefined by the appended claims.

What is claimed is:
 1. A remote vehicle charging system comprising: a) acord reel assembly for selectively providing an electrical cord tofacilitate the extension of a vehicle connector; b) an authorizingdevice for supplying an authorization signal so as to unlock the vehicleconnector; and c) a means for locking connected to the vehicle connectorand electrically connected to the authorizing device to prevent themovement of the vehicle connector in the absence of an authorizationsignal; and d) a control circuit operatively connected to theauthorization device and the means for locking for automaticallypreventing charging through the remote vehicle charging system in theevent of a fault event or in the absence of an authorization signal. 2.The remote vehicle charging system of claim 1, wherein the controlcircuit is housed within the remote vehicle charging system forelectrically connecting the means for locking with the authorizingdevice.
 3. The remote vehicle charging system of claim 2, wherein thecontrol circuit is a master control unit.
 4. The remote vehicle chargingsystem of claim 1 wherein the authorizing device is housed within theremote vehicle charging system.
 5. A remote vehicle charging systemcomprising: a) an electric cord terminating in a vehicle connector; b) acontrol circuit operatively connected to the electric cord forautomatically preventing charging through the remote vehicle chargingsystem in the event of a fault event; and c a self-test circuitconnected to the control circuit for restarting charging through theremote vehicle charging system upon the automatic detection of a validelectrical connection.
 6. The remote vehicle charging system of claim 5,wherein the self-test circuit tests for the presence of a validelectrical connection at a preselected time interval after theconnection of the vehicle connector.
 7. The remote vehicle chargingsystem of claim 5, wherein the self-test circuit tests for the presenceof a valid electrical connection upon reconnection of a vehicleconnector.